scholarly journals The Relative Humidity Effect Of The Reactants Flows Into The Cell To Increase PEM Fuel Cell Performance

2018 ◽  
Vol 156 ◽  
pp. 03033 ◽  
Author(s):  
Mulyazmi ◽  
W.R W Daud ◽  
Silvi Octavia ◽  
Maria Ulfah
Keyword(s):  
Fuel Cell ◽  
Relative Humidity ◽  
Current Density ◽  
Single Cells ◽  
Pem Fuel Cell ◽  
Proton Exchange ◽  
Cell Performance ◽  
Cathode Side ◽  
Humidity Effect ◽  
Fuel Cell Performance

Design of the Proton Exchange Membrane (PEM) fuel cell system is still developed and improved to achieve performance and efficiency optimal. Improvement of PEM fuel cell performance can be achieved by knowing the effect of system parameters based on thermodynamics on voltage and current density. Many parameters affect the performance of PEM fuel cell, one of which is the relative humidity of the reactants that flow in on the anode and cathode sides. The results of this study show that the increase in relative humidity value on the cathode side (RHC) causes a significant increase in current density value when compared to the increase of relative humidity value on the anode side (RHA). The performance of single cells with high values is found in RHC is from 70% to 90%. The maximum current density generated at RHA is 70% and RHC is 90% with PEM operating temperature of 363 K and pressure of 1 atm

The Effect of Variable Catalyst Loading in Electrodes on PEM Fuel Cell Performance

2005 ◽  
Author(s):  
R. Roshandel ◽  
B. Farhanieh
Keyword(s):  
Fuel Cell ◽  
Current Density ◽  
Catalyst Layer ◽  
Pem Fuel Cell ◽  
Pem Fuel Cells ◽  
Cell Performance ◽  
Cathode Side ◽  
Catalyst Loading ◽  
Fuel Cell Performance ◽  
Reactant Concentration

Catalyst layers are one the important parts of the PEM fuel cells as they are the main place for electrochemical reaction taking place in anode and cathode of the cells. The amount of catalyst loading of this layer has a large effect on PEM fuel cell performance. Non-uniformity of reactant concentration could lead to a variation of current density in anode and cathode catalyst layer. The main reason for this phenomenon is porosity variation due to two effects: 1. compression of electrode on the solid landing area and 2. Water produced at the cathode side of diffusion layer. In this study the effect of variable current density in anode and cathode electrode on cell performance is investigated. It has shown that better cell performance could be achieved by adding a certain amount of catalyst loading to each electrode, with respect to the reactant concentration.

Experimental Results of a PEM System Operated on Hydrogen and Reformate

2008 ◽  
Vol 5 (1) ◽  
Author(s):  
M. Minutillo ◽  
E. Jannelli ◽  
F. Tunzio
Keyword(s):  
Fuel Cell ◽  
Natural Gas ◽  
Large Scale ◽  
Pem Fuel Cell ◽  
Proton Exchange ◽  
Operating Conditions ◽  
Cell Performance ◽  
Pure Hydrogen ◽  
Test Bed ◽  
Fuel Cell Performance

The main objective of this study is to evaluate the performance of a proton exchange membrane (PEM) fuel cell generator operating for residential applications. The fuel cell performance has been evaluated using the test bed of the University of Cassino. The experimental activity has been focused to evaluate the performance in different operating conditions: stack temperature, feeding mode, and fuel composition. In order to use PEM fuel cell technology on a large scale, for an electric power distributed generation, it could be necessary to feed fuel cells with conventional fuel, such as natural gas, to generate hydrogen in situ because currently the infrastructure for the distribution of hydrogen is almost nonexistent. Therefore, the fuel cell performance has been evaluated both using pure hydrogen and reformate gas produced by a natural gas reforming system.

Fabrication and Performance Evaluation of Miniaturized Proton Exchange Membrane (PEM) Fuel Cells

2003 ◽  
Author(s):  
Tao Zhang ◽  
Pei-Wen Li ◽  
Qing-Ming Wang ◽  
Laura Schaefer ◽  
Minking K. Chyu
Keyword(s):  
Mass Transfer ◽  
Fuel Cells ◽  
Fuel Cell ◽  
Free Convection ◽  
Current Density ◽  
Pem Fuel Cells ◽  
Proton Exchange ◽  
Cathode Side ◽  
Ohmic Loss ◽  
Fuel Cell Performance

Two types of miniaturized PEM fuel cells are designed and characterized in comparison with a compact commercial fuel cell device in this paper. One has Nafion® membrane electrolyte sandwiched by two brass bipolar plates with micromachined meander-like gas channels. The cross-sectional area of the gas flow channel is approximately 250 by 250 (μm). The other uses the same Nafion® membrane and anode structure, but in stead of the brass plate, a thin stainless steel plate with perforated round holes is used at cathode side. The new cathode structure is expected to allow oxygen (air) being supplied by free-convection mass transfer. The characteristic curves of the fuel cell devices are measured. The activation loss and ohmic loss of the fuel cells have been estimated using empirical equations. Critical issues such as flow arrangement, water removing and air feeding modes concerning the fuel cell performance are investigated in this research. The experimental results demonstrate that the miniaturized fuel cell with free air convection mode is a simple and reliable way for fuel cell operation that could be employed in potential applications although the maximum achievable current density is less favorable due to limited mass transfer of oxygen (air). The relation between the fuel cell dimensions and the maximum achievable current density is also discussed with respect to free-convection mode of air feeding.

Numerical Study on the Influence of Cathode Flow Channel Baffles on PEM Fuel Cell Performance

2016 ◽  
Vol 853 ◽  
pp. 410-415 ◽  
Author(s):  
Xiang Shen ◽  
Jin Zhu Tan ◽  
Yun Li
Keyword(s):  
Fuel Cell ◽  
Electrochemical Performance ◽  
Numerical Study ◽  
Pem Fuel Cell ◽  
Gas Diffusion ◽  
Flow Channel ◽  
Proton Exchange ◽  
Cell Performance ◽  
Fuel Cell Performance ◽  
Flow Channels

A proton exchange membrane (PEM) fuel cell is an electrochemical device that directly converts chemical energy of hydrogen into electric energy.The structure of the flow channel is critical to the PEM fuel cell performance. In this paper, the effect of the cathode flow channel baffles on PEM fuel cell performance was investigated numerically. A three-dimensional model was established for the PEM fuel cell which consisted of bipolar plates with three serpentine flow channels, gas diffusion layers, catalyst layers and PEM. Baffles were added in the cathode flow channels to study the effect of the cathode flow channel baffle on the PEM fuel cell performance. And then, numerical simulation for the PEM fuel cell with various cathode channel baffle heights ranging from 0.2 mm to 0.6 mm was conducted.The simulated results show that there existed an optimal cathode flow channel baffle height in terms of the electrochemical performance as all other parameters of the PEM fuel cell were kept constant. It is found that the PEM fuel cell had the good electrochemical performance as the flow channel baffle heights was 0.4mm in this work.

Multiphysics Modeling of Assembly Pressure Effects on Proton Exchange Membrane Fuel Cell Performance

2009 ◽  
Vol 6 (4) ◽  
Author(s):  
Y. Zhou ◽  
G. Lin ◽  
A. J. Shih ◽  
S. J. Hu
Keyword(s):  
Mass Transfer ◽  
Fuel Cell ◽  
Contact Resistance ◽  
Electrical Contact ◽  
Pem Fuel Cell ◽  
Proton Exchange ◽  
Cell Performance ◽  
Pressure Effects ◽  
Electrical Contact Resistance ◽  
Fuel Cell Performance

The clamping pressure used in assembling a proton exchange membrane (PEM) fuel cell stack can have significant effects on the overall cell performance. The pressure causes stack deformation, particularly in the gas diffusion layer (GDL), and impacts gas mass transfer and electrical contact resistance. Existing research for analyzing the assembly pressure effects is mostly experimental. This paper develops a sequential approach to study the pressure effects by combining the mechanical and electrochemical phenomena in fuel cells. The model integrates gas mass transfer analysis based on the deformed GDL geometry and modified parameters with the microscale electrical contact resistance analysis. The modeling results reveal that higher assembly pressure increases cell resistance to gas mass transfer, causes an uneven current density distribution, and reduces electrical contact resistance. These combined effects show that as the assembly pressure increases, the PEM fuel cell power output increases first to a maximum and then decreases over a wide range of pressures. An optimum assembly pressure is observed. The model is validated against published experimental data with good agreements. This study provides a basis for determining the assembly pressure required for optimizing PEM fuel cell performance.

A Numerical Simulation of Proton Exchange Membrane Fuel Cell Performance

2011 ◽  
Vol 347-353 ◽  
pp. 376-385
Author(s):  
Shi Gang Yu ◽  
Hui He ◽  
You Sheng Xu
Keyword(s):  
Numerical Simulation ◽  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Flow Direction ◽  
Proton Exchange ◽  
Cell Performance ◽  
Cathode Side ◽  
Operating Pressure ◽  
Fuel Cell Performance ◽  
Exchange Membrane

A composite three-dimensional mathematical model of proton exchange membrane fuel cell is proposed, the corresponding finite element method and numerical simulation are given as well, where fluid flow, proton transport, and electrochemical reaction are addressed. Some factors that probably affect the performance of the cell are analyzed by using the model. The computational results show that the reactant concentration decreases along the flow direction, the water concentration increases in the cathode side of membrane, membrane resistance decreases, conductivity increases and proton concentration increases. The fuel cell performance is better when the porosity increases, as well as the operating pressure.

Key parameters of active layers affecting proton exchange membrane (PEM) fuel cell performance

Energy ◽  
2008 ◽  
Vol 33 (12) ◽  
pp. 1794-1800 ◽  
Author(s):  
Jarupuk Thepkaew ◽  
Apichai Therdthianwong ◽  
Supaporn Therdthianwong
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Pem Fuel Cell ◽  
Proton Exchange ◽  
Cell Performance ◽  
Fuel Cell Performance ◽  
Active Layers ◽  
Exchange Membrane

Effects of Flow Field and Diffusion Layer Properties on Water Accumulation in a PEM Fuel Cell

2007 ◽  
Author(s):  
J. P. Owejan ◽  
T. A. Trabold ◽  
D. L. Jacobson ◽  
M. Arif ◽  
S. G. Kandlikar
Keyword(s):  
Fuel Cell ◽  
Flow Field ◽  
Pem Fuel Cell ◽  
Gas Diffusion ◽  
Proton Exchange ◽  
Cell Performance ◽  
Water Volume ◽  
Fuel Cell Performance ◽  
Diffusion Media ◽  
And Diffusion

Water is the main product of the electrochemical reaction in a proton exchange membrane (PEM) fuel cell. Where the water is produced over the active area of the cell, and how it accumulates within the flow fields and gas diffusion layers, strongly affects the performance of the device and influences operational considerations such as freeze and durability. In this work, the neutron radiography method was used to obtain two-dimensional distributions of liquid water in operating 50 cm2 fuel cells. Variations were made of flow field channel and diffusion media properties, to assess the effects on the overall volume and spatial distribution of accumulated water. Flow field channels with hydrophobic coating retain more water, but the distribution of a greater number of smaller slugs in the channel area improves fuel cell performance at high current density. Channels with triangular geometry retain less water than rectangular channels of the same cross-sectional area, and the water is mostly trapped in the two corners adjacent to the diffusion media. Also, it was found that cells constructed using diffusion media with lower in-plane gas permeability tended to retain less water. In some cases, large differences in fuel cell performance were observed with very small changes in accumulated water volume, suggesting that flooding within the electrode layer or at the electrode-diffusion media interface is the primary cause of the significant mass transport voltage loss.

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